The primary function of a push broom is to sweep large areas. One of the problems with existing push broom designs is that debris is left behind after the broom makes a single pass in the forward sweeping direction. To sweep up the left-behind debris, a user must make multiple passes with the broom, lifting the broom in a circular type motion, pulling it back toward the user, and re-sweeping much if not all of the same area as was originally swept.
Over the years, alternative sweeping devices have been developed to allow users to sweep large areas more efficiently. Many of the alternative sweeping devices require external power or incorporate bins for capturing debris, neither of which is desirable in a lot of cases.
One example of a manually operated rotary broom is disclosed in U.S. Pat. No. 4,864,674 to Hamilton. The broom includes a removable disc with blades and a locking arrangement that, depending in part on the angle of the handle, locks and unlocks to provide a standard push broom mode and a continuous rotation pick-up (dustpan) mode. The dustpan mode deposits debris in a cylinder housed between the wheels. The disc and wheels share a common centerline.
Another example of a manually operated rotary broom is disclosed in U.S. Pat. No. 8,156,596 B2 to Rose. The broom includes a pre-adjusted cylindrical brush height as well as gearing that permits the cylindrical brush to rotate at a faster rotational speed than, and in a opposite direction to, the wheels but not disengage from the wheels. When the broom is operated in the forward sweeping direction the cylindrical brush sweeps debris ahead of itself, away from the user. However, faster rotational speed can cause debris to be thrown too far ahead of the broom and fine debris to rotate back around the brush and be left behind by the broom. When the broom is pulled back toward the user, the brush continues to rotate and now sweeps some of the debris back toward the user. In the cylindrical brush's highest position, the centerline of the wheels and that of the brush are in the same horizontal plane with the brush centerline leading the wheels. In the brush's lowest position, the centerline of the brush is below that of the wheels.